Effect of the substitution of Co for Fe on phase components and magnetic properties of melt-spun Pr9Fe85B5 nanocomposites

The phase evolution and magnetic properties of melt-spun Pr9Fe86-xCoxB5 (x=0,6,10,12,14,16) nanocomposites have been investigated. It was found that substitution of Co for Fe obviously raises the magnetization (M, H=6.5T), from 1.50 T for x=0 to 1.80 T for x=12. At the same time, the remanence (M-r), intrinsic coercivity (H-c) and maximum energy product (BHmax) changes from 0.96 T, 5.69 kOe, 11.8 MGOe for x=0 to 1.15T, 6.33 kOe, 17.3 MGOe for x=12, respectively. Further substitution of Co for Fe results in a decrease of M-r and BHmax because of the presence of minor amounts of 1:5 and 2:17 phases. Thermomagnetic analysis shows that the Co atoms enter into both the magnetically hard and soft phases. The Curie temperature of the hard magnetic phase increases linearly by increasing Go-substitution at the rate of DeltaT(c)=9 degreesC/at% Pr. (C) 2001 Elsevier Science B.V. All rights reserved.